Hardy, who fought less than a week ago in Boston in a controversial fight which saw his win commuted to a no-contest after an inhaler he used in between rounds was subsequently deemed illegal, will have less than three weeks to prepare to face the 30-7 Volkov but despite the sizeable step up in competition, he says that the fight will add another knockout to his record.
Volkov was initially scheduled to face former heavyweight champ Dos Santos in the UFC Moscow headliner on November 7 but a bacterial infection in his left leg ruled the Brazilian out of the contest, forcing UFC matchmakers to scramble to find a replacement.
Step up Greg Hardy.
"I'm excited. There was a lot of things that played into this decision, dude," he said to TMZ Sports.
"The big one was just the opportunity. This is a big-time fight, this is high-level competition.
"My teammate (Dos Santos) went down so somebody's got to fill in. The next man up has got to fill in. That has just always been my mentality. I'm holding down for the team, the UFC always has my back. They took a gamble on me, do you know what I mean? They let me in the door. They need somebody to fill in and for sure I'm going to go and knock the guy out."
On paper, the task is an uphill one for the American. Volkov has nearly 40 professional fights under his belt and owns wins against the likes of Fabricio Werdum, Stefan Struve and Roy Nelson. The Moscow native was 11 seconds from victory in his last fight a year ago with Derrick Lewis before suffering a sensational KO as the clock ticked towards the fight's conclusion.
And this result, Hardy says, gives him confidence.
"Derrick Lewis knocked this dude out," he explained.
"If pillow-hands Lewis can do it, for sure I feel like I can go in there and compete and knock this guy out.
"It's time to step up and put my mettle to the test as 'The Prince of War'. Stop talking, put the hands up and fight with an actual monster. I'm fighting with a top-ranked elite assassin."
But this isn't personal. Hardy is gracious in recognizing that Volkov didn't have to accept the fight, which will be his fifth UFC bout this calendar year - an all-time record for a heavyweight.
"Thank you for accepting the fight, bro. Let's go to war. I can't wait. I'm excited. See you in Russia, my friend."